The Dallmeyer 76mm f/2.8 Oscillograph is a specialist fixed-focal-length lens made by the long-established London optical maker J.H. Dallmeyer. As its name indicates, it was designed for oscillograph and instrumentation recording work rather than general pictorial photography, capturing cathode-ray traces and similar high-contrast subjects at close to 1:1 reproduction.

Today this is a niche industrial lens with a thin auction record, and hammer prices for clean copies at UK auction have ranged from £69 to £119, putting the median around £94. Because it lacks a standard photographic mount and a wide buyer base, even tidy examples sell for modest sums at saleroom level, and condition matters far more than provenance to what it is worth.